1. Field of the Invention
The present invention relates to oil burners and more particularly to an oil burner system that will prevent or reduce problems such as soot accumulation due to unlimited recycling under inadequate combustion conditions.
2. Description of the Prior Art
In our co-pending patent application entitled xe2x80x9cPump Purge for Oil Primaryxe2x80x9d, Ser. No. 09/621,257 filed and Jul. 21, 2000 assigned to the assignee of the present invention, an oil burner system which provides hardware and software that allows the system to be quickly primed or purged when necessary without entering a number of unwanted lockouts is described and claimed. In the normal operation of that system, after xe2x80x9cPower Onxe2x80x9d occurs and various checks are made, an xe2x80x9cIdle Statexe2x80x9d is entered where the system awaits a xe2x80x9ccall for heatxe2x80x9d from a thermostat. When this arrives, a controller starts the ignition process, the flame is established and the system goes to a normal xe2x80x9cRun Statexe2x80x9d in which the furnace supplies heat until the call for heat from the thermostat disappears. Sometimes in the normal Run State, the flame can go out before the call for heat from the thermostat ends. This is usually caused by a transitory condition such as an air bubble in the fuel line. When the flame in the burner goes out after having been established and before the thermostat stops calling for heat, the system goes into a xe2x80x9cRecycle Statexe2x80x9d which, after a delay (recycle time), the system reverts to the Idle State where it receives the continued call for heat from the thermostat and the controller starts the ignition process and again initiates a flame. The system then returns to its normal Run State. Unfortunately, the condition causing the flame out may not have disappeared; for example when the system does not support combustion after the igniter turns off. When this occurs, the flame will again extinguish putting the system back in the Recycle State again and an endless cycle to the Run State, the Recycle State, the Idle State etc. may occur. This endless recycling is often due to a poor combustion situation and thus excessive soot may develop, excessive wear on components may result, and other damage may occur.
The present invention overcomes the above problems by providing a recycle limit on the number of times that the system can recycle during a predetermined period.
This is accomplished with a recycle timer and logic for the microprocessor in the Primary Control so that the oil burner is restricted to going through the recycle mode a predetermined number of times (for example three), unless the call for heat is satisfied or power is removed. If the system enters the Recycle State more than the predetermined number of times it will go into a xe2x80x9cLockout Statexe2x80x9d that requires manual intervention to reset the control.